1. Field of the Invention
Applicant's invention relates to an ultra fine mineral compound and a method of processing native Dead Sea minerals into this ultra fine mineral compound that can be used to manufacture all-natural Dead Sea mineral compositions particularly compositions for use in cosmetic preparations such as bath and body products.
2. Background Information
A cosmetic product is any substance or preparation intended for placing in contact with the various external parts of the human body or with the teeth or mucous membranes of the oral cavity with the intention of cleaning, perfuming, or protecting, to keep such parts in good condition, change their appearance or correct body odors. There are numerous product groups that fall within the category of cosmetic products or preparations, including but not limited to cosmetic emulsions, deodorants and antiperspirants, sunscreens, make-up preparations, hair preparations, bath products, soaps, exfoliating agents, and shaving preparations.
Cosmetic preparations are usually mixtures. A mixture is any matter consisting of two or more substances physically combined in some proportion by mass. In a mixture there is no chemical reaction. Two types of mixtures are heterogenous mixtures and homogenous mixtures. A heterogenous mixture is a mixture having ingredients of different states of matter. A suspension is a heterogenous mixture in which droplets or particles are suspended in a liquid. A colloidal dispersion is a specific type of suspension in which the particles or droplets of one substance are smaller than those in suspensions, but larger than those in solutions and that have one dimension in the range of 1 to 10 nm. A homogenous mixture is a mixture having ingredients of the same states of matter. Homogenous mixtures are usually solutions which are made up of a solute dissolved in a solvent. When the solute does not remain dissolved in the solvent the mixture is in turn referred to as a heterogenous mixture.
Many cosmetic preparations are suspensions and more particularly colloidal dispersions. In a colloidal dispersion there is a suspension of finely divided particles in a continuous medium in which the particles do not settle out of the substance rapidly and are not readily filtered. Where the particle is a liquid droplet and the medium is a liquid, the colloid is referred to as an emulsion. If however the particle is a solid and the medium is a liquid, the colloid is referred to as a sol or gel. A sol is a colloidal dispersion of a solid in a liquid in which the particles are so small that the dispersion appears transparent while a gel is a suspension that behaves as an elastic solid or semi-solid rather than liquid.
Colloidal systems undergo agglomeration, or gathering into a mass, leading to a distribution of droplet size for liquid colloids. Though wetting phenomena and nonwetting colloidal factors may play a role, the agglomeration process is induced by particulate collisions arising from diffusion, as in Brownian motion, velocity or shear gradients in a liquid dispersion medium, and gravitational settling.
Irreversible agglomeration can be quantified using various models for repulsive or attractive electrostatic, London-van der Waals, and steric forces which affect stabilization of aqueous and nonaqueous colloidal systems. A comprehensive model of colloidal stability, the DLVO (Derjagiun-Landau-Verwey-Overbeek) model has provided information regarding the roles of electrolytes, dielectric constant, and other physical quantities in colloidal systems. This theory considers the electrostatic interactions between two identically charged, suspended particles to be repulsive and to arise from the overlap of the electrical double layers associated with each particle.
For systems containing a soluble polymer or surfactant, molecular arrangement, thickness of the absorbed layer, temperature, and chain or segment solvation are additional critical parameters in determining the effectiveness of a dispersed agent in providing steric stabilization. If velocity or shear gradients are present, such as in mixing, and are sufficiently large, the frequency of collisions depends on the volume fraction of solids and the mean velocity gradient. Assuming that sedimentation is slow compared to the first two collision mechanisms, the overall agglomeration rate is−dN/dt=kdN2+ksN 
where N is the particle number concentration, kd and ks are the respective rate constants corresponding to diffusion controlled and shear induced collision processes, and the minus sign denotes that the particle number concentration decreases with time.
Cosmetic emulsions, such as lotions and creams, are emulsions of water-based and oil-based phases. An emulsion is more particularly a two phase system consisting of two incompletely miscible liquids, the internal or discontinuous phase dispersed as finite globules in the other termed the continuous phase. Emulsions can be classified according which liquid is dispersed in the continuous phase. Oil in water (o/w) emulsions have oil as the dispersed phase in water as the continuous phase. In water in oil (w/o) emulsions, the water is dispersed in the oil as the continuous phase.
Products that produce emulsions, or emulsifiers, can be classified as ionic or nonionic according to their behavior. An ionic emulsifier is composed of an organic lipophilic group and a hydrophilic group. The hydrophilic-lipophilic balance is often used to characterize emulsifiers and related surfactant materials. The ionic types may be further divided into anionic and cationic, depending on the nature of the ion-active group. The lipophilic portion of the molecule is usually considered to be the surface active portion. Nonionic emulsifiers are completely covalent and show no apparent tendency to ionize. Emulsifiers, being surface active agents, lower surface and interfacial tensions and increase the tendency of their solution to spread.
Mixing of cosmetic preparations is an important operation particularly in the preparation of heterogeneous mixtures such as suspensions and colloids since the actual steps involved can dictate whether the particles or droplets remain suspended continuously throughout the medium for a reasonable period of time to maintain an adequate shelf life and viability of the preparation. This becomes increasingly difficult when the desire of the manufacturer is to produce cosmetic preparations that contain all natural ingredients. Natural ingredients refer to ingredients obtained from nature such as extracted directly from plants or animal products as opposed to being produced synthetically.
The present composition contains all natural ingredients. One of the natural ingredients incorporated into the composition of the present invention is Dead Sea minerals. Dead Sea minerals are not to be confused with sea salt or Afrosalt® which has a different chemical composition. Sea salt is the compound remaining when oceanic sea water is evaporated, and contains primarily sodium and chloride and in some cases trace amounts of copper, manganese, nickel, fluorine, tin and iodine. The trace minerals can vary based upon the source of the sea water. Afrosalt® is a compound of inorganic salts derived from seawater containing 45%±31 sodium, 53%±3 chlorides, 3.6% magnesium, <7% sulphates, <3% calcium, <2% bromides, 0.49%±0.04 potassium, <0.3% iodides. The Dead Sea is a unique body of water, unlike any other and has a singular chemical composition. For years it has been known that treatments administered at the Dead Sea can bring about significant remissions in diseases such as psoriasis, psoriatic arthritis, rheumatoid arthritis, and osteoarthritis. It is not known what the mode of action is of the Dead Sea minerals. It is however believed that specific ions from the minerals play a role mainly as co-factors in enzymatic regulation activities in the metabolism of healthy skin. There are indications that magnesium is a co-factor for phosphate transferring enzymes and participates in c-AMP c-GMP balancing regulation, potassium may enhance CO2 transport, and calcium is thought to regulate cell membrane permeability. Zinc may play a role as a co-factor in cell proliferation enzymatic regulation.
Electrolytes can be absorbed into the skin from mineral rich preparations. The skin is a multilayered membrane with certain absorption characteristics which are subject to change. Corneum cell walls are involved in the semi-permeable membrane system and are responsible for the osmotic properties of the corneum. The penetration of the electrolytes through the stratum corneum occurs in between the horny cells.
There are models that demonstrate specific ionic absorption through the human skin barrier. Concentration is the key. When applying a cosmetic preparation, the relevant concentration is the concentration gradient between each specific dissolved ion both outside and inside the skin surface. During the absorption process, a partitioning of minerals occurs from the vehicle to the skin. The nature of the cosmetic preparation is significant in determining the kinetics of mineral skin penetration. Another important factor is the pH in the various microenvironments of the skin. Ions in varying valences and cations in combination with different anions penetrate to differing extents. There are major differences in the extent of skin penetration in different areas of the body.
The face is one of the highest absorbing areas. Exposed surface area, frequency of dermal application, skin type, skin age, temperature, and contact time should be considered. Factors involved in the percutaneous absorption of cosmetic preparations include use of other topical or systemic drugs, application parameters such as area, amount, frequency, massage; formulation such as concentration, nature of the vehicle, occlusivity, pH; formulation components such as solvents, surfactants, perfumes, dyes, inert ingredients, active ingredients, preservatives, impurities; skin damage such as abrasion, detergents, organic solvents, climatic factors; and physiological factors such as nature of the skin, anatomical site, individual factors and hydration. Assuming electrolytes can be absorbed into the skin, dermal application of mineral rich cosmetics can prove beneficial. The goal therefore has been to incorporate the beneficial properties of the Dead Sea into cosmetics.
Over the past few years cosmetics have been marketed that incorporate Dead Sea minerals, including body and face masks with highly viscous dispersions, lotions and creams with the minerals in very low concentrations, and one phase aqueous solutions with the minerals in very low concentrations. The composition of Dead Sea minerals is very unique. The concentration of the divalent cations magnesium and calcium is very high compared with the monovalent cations, mainly sodium and potassium. In addition, the ionic strength of a solution of these minerals is very high. These two factors have a tremendous negative effect on the formation and stability of dispersions and emulsions, and strictly limit their concentration to a few percent of the weight of conventional cosmetic formulations.
As mentioned previously, according to the DLVO theory stabilization of dispersions of emulsions can be described as the result of the combined attraction and repulsion forces between the particles or droplets that are dispersed in continuous phases. For example, oil in water emulsions can be stabilized by the absorption of ionic surfactants onto the oil droplet surface which may become positively or negatively charged. The electric surface potential will cause repulsion between the approaching droplets. If the repulsion forces overcome the attraction forces the emulsion will be stable. The electric surface potential is strongly dependent on electrolyte concentration and on the valence of the counter ion in the solution. Therefore, the electrical repulsion is significantly reduced in systems that contain high concentrations of electrolytes in general, and divalent counterions in particular. This results in difficulties in formulating a cosmetic emulsion that contains electrolytes from the Dead Sea that is rich in magnesium and calcium divalent cations at high concentrations, and will be stable for the minimum required shelf life for a cosmetic product. In addition, the high concentration of electrolytes may cause salting out and precipitation of various components of any cosmetic preparation. This may also affect the texture and the appearance of the product, its viscosity, hydrophilic-lipophilic balance, crystallization, etc.
The present invention provides for a chemical composition for application to the skin comprising a mixture of at least 50% processed ultra fine Dead Sea mineral particles in a continuous all natural carrier medium where in the Dead Sea mineral particles do not rapidly settle out of the carrier medium which promotes a more shelf stable product. This chemical composition takes advantage of the ionic properties of the Dead Sea minerals and contains minerals of such a fine granularity that exfoliation is not as harsh to the skin, particularly of persons suffering from severe skin disorders. In addition, the carrier medium of the present invention contains all natural ingredients and is non-comedogenic so consumers do not have to be concerned about clogged pores.
The problems of the prior art are overcome by the present invention by processing the Dead Sea minerals into an ultra fine mineral compound and mixing this ultra fine mineral compound with select natural ingredients using a unique swift heating, chilling and mixing technique to produce cosmetic preparations, such as body scrubs, rubs, muds, creams, lotions, and related preparations. These cosmetic preparations contain greater than 50% concentration of Dead Sea minerals but maintain stability and preferable shelf life with a pleasant feel for the consumer.